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Thread: Can you run a pump too slow?

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    Can you run a pump too slow?

    1st off I'm glad I found this site. It’s been very helpful so far. I am going to move to the BBB method and ordered my TF-100 kit yesterday, I even got the SpeedStir (ill be like a kid on Christmas when my kit arrives). Anyway back to my question...

    My pool was finished in November 2011 and we 1st used the spa in late December. I have been keeping the filter pump at 90% when I run it but this weekend I stated playing with the various speeds (full equipment list in the sig file).

    here is a breakdown of the Watts used and filter PSI based on the % I have the filter pump set too.
    Power - watts - PSI
    100% - 2160W - 28
    90% - 1600W - 22
    70% - 755W - 14
    60% - 474W - 10
    50% - 276W - 6
    45% - 202W - 4.5
    40% - 152W - 3
    35% and under psi not reading.

    my plan for the summer is as follows but I would like your thoughts on this.

    filter pump 60% 11am-1pm
    filter pump 90% and cleaner 1pm-3pm
    filter pump 60% 3pm-5:30pm

    Will everything filter properly/efficiently running the pump at 60%? Do I need to make sure the filter pressure is at a certain level to verify things are working properly? Based on this am I moving enough water throughout the day?

    I'm sure you guys may need more info but I'm not sure what else to provide so ask away.

    Thanks for your help
    21,000 gallon pool w/spa, Pebble Sheen, Hayward EcoStar variable speed filter pump, Hayward DE6020 Filter, Hayward 400FDN Heater, Stenner pump with 15 gallon tank, Clear O3 ozone system, Hayward Goldline PS-8 controller, Hayward 6060 cleaner pump, Polaris 280 cleaner, Hayward EcoStar variable speed water feature pump.

  2. Back To Top    #2
    susa's Avatar
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    Re: Can you run a pump too slow?

    I run IntelliFlow VF at 95 watts 24 hours for 3 days a week

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    JasonLion's Avatar
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    Re: Can you run a pump too slow?

    Welcome to TFP!

    As susa said, you can run your pump at a much lower speed than that. The EcoStar is most efficient at about 900 rpm. The lower speed limit is mostly a question of skimmer efficiency and creating enough flow to keep your heater happy (when you are using the heater). At extremely low speed the skimmer(s) stop skimming efficiently. When using the heater, you will need to run somewhat faster than the skimmers require to keep the heater happy. The PS-8 will allow you to setup minimum speeds to normal use and for when the heater is on.

    You also need to more enough total water through the filter to keep the water clean. Typically the best way to do this is somewhere between 12 and 24 hours a day at a very low speed.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
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    Re: Can you run a pump too slow?

    so are you guys suggesting going even slower but increasing the run time right. Aside from the heater (I understand the thought behind running flow higher with the heater)

    Also I noticed the following at 60%.
    I did have suction at both skimmers.
    I could feel return water from about 6 inches out.
    Filter pressure was at 10% (and its due for a cleaning based on normal run pressure)
    now the chlorinator was interesting. I have 3 tablets in it and noticed the water level was barley above the top tablet. I usually unscrew the cap a bit and it quickly fill back up then i tighten but when I did this the water level actually dropped. (I can only assume because of slower flow rate) is this a concern?

    I raised the pump to 70% noticed the following
    unscrewing the chlorinator cap filled the reservoir. (Also I have the dial set to 4 on the chlorinator so almost all the way open.)
    filter pressure was around 12psi
    I could feel flow from returns at about 9 inches out.
    21,000 gallon pool w/spa, Pebble Sheen, Hayward EcoStar variable speed filter pump, Hayward DE6020 Filter, Hayward 400FDN Heater, Stenner pump with 15 gallon tank, Clear O3 ozone system, Hayward Goldline PS-8 controller, Hayward 6060 cleaner pump, Polaris 280 cleaner, Hayward EcoStar variable speed water feature pump.

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    Mod Squad jblizzle's Avatar
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    Re: Can you run a pump too slow?

    Based on the skimmer action, seems like you could dial back some more.

    I think the only concern I have out of reading this is that you are using a tablet feeder ... please keep an eye on your CYA levels before they get out of hand and the chlorine that is added via the tablets is not enough to actually keep your water clear and require a pool drain/fill.

    Although I see you are switching to the BBB method ... so hopefully that will result in not using the chlorinator at all and hopefully your CYA is not already too high.
    Jason, TFP Moderator
    18k IG pebblesheen pool, Hayward ProLogic P4 w/ T-15 SWG, Pentair 1HP 2-speed Superflo, Hayward 6020 DE filter
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    Mod Squad Bama Rambler's Avatar
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    Re: Can you run a pump too slow?

    The chlorinator not being full isn't a problem. As long as it's providing enough FC for your CYA level it's ok. Having said that, you should stop using the chlorinator except on special occasions like vacations, etc.. Once you have the test kit and post a set of results we can offer more advice.

    As said before you can run your pump really slow and keep it running 24/7 and it'll still be fine. Be biggest determining factor in how fast you need to run it is proper circulation. If running it too slow allows part of the water to be stagnant (i.e. a corner) then you'll need to run it a little faster.
    Dave J. TFP Moderator
    24' x 52" Round AGP. 2hp/hp SPL Power-Flo 2-speed pump. 200sqft Waterway Cartridge Filter. 45MHP2(3GPD) Stenner Peristaltic Pump
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    Re: Can you run a pump too slow?

    Thanks for all the advise. I added to my 1st post to show slower speeds as well as the filter pressure at the various percentages. If I go really low I get no PSI at all.

    I am leaning toward running the following.

    45% 8:30am to 12:30pm
    90% plus cleaner 12:30pm-1-45pm
    45% 1:45pm-8:30pm.

    This is way less power than running it at 90% for 4-5 hours a day (as the pool places suggest). I guess I need to somehow determine how much water I am actually circulating.

    Also is there some test that can be done to determine if at low speeds some water in the pool may be sitting still?

    Thanks.
    21,000 gallon pool w/spa, Pebble Sheen, Hayward EcoStar variable speed filter pump, Hayward DE6020 Filter, Hayward 400FDN Heater, Stenner pump with 15 gallon tank, Clear O3 ozone system, Hayward Goldline PS-8 controller, Hayward 6060 cleaner pump, Polaris 280 cleaner, Hayward EcoStar variable speed water feature pump.

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    mas985's Avatar
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    Re: Can you run a pump too slow?

    90% is still pretty high and my first guess is around 77 GPM. Are you sure you really need that much flow rate? Even cleaners usually don't need that much.

    If you want some flow rate estimates, I need some additional information:

    Pad height relative to the water level.
    Suction side plumbing description including: Pipe sizes, number of runs from the pool to pad and length of runs.

    The rest I got from your posts.
    Mark
    Hydraulics 101; Pump Ed 101; Pump/Pool Spreadsheets; Pump Run Time Study; DIY Acid Dosing; DIY Cover Roller
    18'x36' 20k plaster, MaxFlo SP2303VSP, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater

  9. Back To Top    #9

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    Re: Can you run a pump too slow?

    Mark I suspect 90% is more than I need. I do know the spa waterfall and bubblers looks best at 90% or higher (and I have to starve the pool returns for the spa waterfall to look good even at 90%). But for regular filtering and cleaning you are probably right its way more than whats needed. Here are some pictures that might help as well as some answers to your questions.

    The equipment is about level with the pool deck and is about 65 ft away from the pool on the side of the house. The raised spa is actually higher than the pumps. (found that out while cleaning the pump basket one day)
    Here are some pictures. Thanks again to all for the help.

    pump intake side


    pool return side


    the pool with 18" raised spa. Pool is roughly 31'x17'


    full image pad and other pictures are in the pool album
    http://s638.photobucket.com/albums/uu106/cajun321/pool/
    21,000 gallon pool w/spa, Pebble Sheen, Hayward EcoStar variable speed filter pump, Hayward DE6020 Filter, Hayward 400FDN Heater, Stenner pump with 15 gallon tank, Clear O3 ozone system, Hayward Goldline PS-8 controller, Hayward 6060 cleaner pump, Polaris 280 cleaner, Hayward EcoStar variable speed water feature pump.

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    linen's Avatar
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    Re: Can you run a pump too slow?

    Welcome to tfp, Cajun

    That is a great looking pool you have there I love the multiple fountains.

    Just for my curiosity since I am sure Mark and others can understand without, but could you take a picture that shows the whole pad? I am a wee bit confused (normal for me) by some of the "extra" pipes like the one on the second to last picture that crosses over the whole pad.
    TFP Expert who uses Pool School and my TF100 test kit along with PoolMath for my: Round 11K gallon AGP with deep end, 20" sand filter, Matrix 1hp 2spd, 6 2ftX20ft solar panels (and solar cover!), Intex SWCG (copper bars disconnected) and a Rubadub hot tub (chlorine). The SLAM process is not finished until: 1. CC < 0.5 ppm, 2. An OCLT < 1.0 ppm and, 3. The water is crystal clear.

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    Mod Squad jblizzle's Avatar
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    Re: Can you run a pump too slow?

    Quote Originally Posted by linen
    I am a wee bit confused (normal for me) by some of the "extra" pipes like the one on the second to last picture that crosses over the whole pad.
    In the photo bucket album it looks like the low long pipe goes up to an air blower.
    Jason, TFP Moderator
    18k IG pebblesheen pool, Hayward ProLogic P4 w/ T-15 SWG, Pentair 1HP 2-speed Superflo, Hayward 6020 DE filter
    500 sqft Heliocol solar panels, ThePoolCleaner, TF-100 test kit w/ SpeedStir
    Pool School + Test Kit + PoolMath = A TROUBLE FREE POOL
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    linen's Avatar
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    Re: Can you run a pump too slow?

    Quote Originally Posted by jblizzle
    In the photo bucket album it looks like the low long pipe goes up to an air blower.
    Thanks jbliz, I missed the part about the album Makes much more sense now and a do not need anymore pictures.
    TFP Expert who uses Pool School and my TF100 test kit along with PoolMath for my: Round 11K gallon AGP with deep end, 20" sand filter, Matrix 1hp 2spd, 6 2ftX20ft solar panels (and solar cover!), Intex SWCG (copper bars disconnected) and a Rubadub hot tub (chlorine). The SLAM process is not finished until: 1. CC < 0.5 ppm, 2. An OCLT < 1.0 ppm and, 3. The water is crystal clear.

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    Re: Can you run a pump too slow?

    Quote Originally Posted by linen
    Welcome to tfp, Cajun

    That is a great looking pool you have there I love the multiple fountains.
    Thanks we are very happy with the way it turned out.

    Jason was right its a blower, I added another picture in the album. Unfortunatly I can't get a straight shot of the entire pad because there is only about 2.5 ft from the pad to the fence.
    21,000 gallon pool w/spa, Pebble Sheen, Hayward EcoStar variable speed filter pump, Hayward DE6020 Filter, Hayward 400FDN Heater, Stenner pump with 15 gallon tank, Clear O3 ozone system, Hayward Goldline PS-8 controller, Hayward 6060 cleaner pump, Polaris 280 cleaner, Hayward EcoStar variable speed water feature pump.

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    linen's Avatar
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    Re: Can you run a pump too slow?

    No problem on the pictures, I saw what I wanted when I went to photobucket.
    TFP Expert who uses Pool School and my TF100 test kit along with PoolMath for my: Round 11K gallon AGP with deep end, 20" sand filter, Matrix 1hp 2spd, 6 2ftX20ft solar panels (and solar cover!), Intex SWCG (copper bars disconnected) and a Rubadub hot tub (chlorine). The SLAM process is not finished until: 1. CC < 0.5 ppm, 2. An OCLT < 1.0 ppm and, 3. The water is crystal clear.

  15. Back To Top    #15

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    Re: Can you run a pump too slow?

    So for the past week (aside from using the heater over the weekend) I have been running my pump as follows.

    7:30am - 1pm - 45%
    1pm - 2:15 - 75% - cleaner also running
    2:15 - 10pm 45%

    The water is extremely clear and sparkles. I am guessing it's because the water is circulating for so long rather than sitting? Based on my current rate 8.3 cents per kWh I am using under $10 a month in electricity to run the pool (assuming my calculations are correct).

    For you guys running your pools 24/7 are you noticing you don't really need the pool cleaner As much. It seems the skimmer catches most everything before it has time to sit and sink?
    21,000 gallon pool w/spa, Pebble Sheen, Hayward EcoStar variable speed filter pump, Hayward DE6020 Filter, Hayward 400FDN Heater, Stenner pump with 15 gallon tank, Clear O3 ozone system, Hayward Goldline PS-8 controller, Hayward 6060 cleaner pump, Polaris 280 cleaner, Hayward EcoStar variable speed water feature pump.

  16. Back To Top    #16
    linen's Avatar
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    Re: Can you run a pump too slow?

    Other than sand those meddling kids drag in I doubt I would need to vacuum/clean much at all other than in late fall. I run 24/7 on low and get great circular water movement...that is when my pool isn't winterized (which it still is ).
    TFP Expert who uses Pool School and my TF100 test kit along with PoolMath for my: Round 11K gallon AGP with deep end, 20" sand filter, Matrix 1hp 2spd, 6 2ftX20ft solar panels (and solar cover!), Intex SWCG (copper bars disconnected) and a Rubadub hot tub (chlorine). The SLAM process is not finished until: 1. CC < 0.5 ppm, 2. An OCLT < 1.0 ppm and, 3. The water is crystal clear.

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